JPWO2009016937A1 - Chip coil parts - Google Patents

Abstract

Provided is a chip-type coil component that can reduce the resistance value of a coil without reducing the inductance value of the coil as much as possible. The magnetic layer (20) constitutes a laminate. The internal electrode (26) is laminated on the magnetic layer (20) and is connected to each other to form a coil (L). The auxiliary internal electrode (30) is laminated on the magnetic layer (20) on which the internal electrode (26) is laminated. The auxiliary internal electrode (30) is connected in parallel to the internal electrode (26) stacked on the magnetic layer (20) different from the magnetic layer (20) on which the auxiliary internal electrode (30) is stacked. Has been.

Description

  The present invention relates to a chip-type coil component with a built-in coil.

  As a conventional chip-type coil component, a multilayer chip inductor described in Patent Document 1 has been proposed. A conventional multilayer chip inductor will be described below with reference to FIG. FIG. 9 is an exploded perspective view of the multilayer chip inductor.

  As shown in FIG. 9, in the multilayer chip inductor, two magnetic layers 101 each having an internal electrode 102 having the same shape are disposed so as to overlap each other. The two internal electrodes 102 having the same shape are electrically connected to each other via via-hole conductors 103 at both ends except for the upper and lower two layers which are the outermost layers. Furthermore, each internal electrode 102 is electrically connected in series via the via-hole conductor 103 to form a spiral coil L. Note that one end of each of the upper and lower internal electrodes 102 as the outermost layer is formed so as to be drawn to one side of the magnetic layer 101 and connected to an external electrode (not shown). According to the multilayer chip inductor, since the two internal electrodes 102 having the same shape are connected in parallel, the resistance value of the coil L can be lowered.

However, in the multilayer chip inductor, since two magnetic layers 101 each having the same shape of the internal electrode 102 are laminated, the axial length of the coil L becomes long. Since the inductance value of the coil L is inversely proportional to the axial length, when the axial length increases, the inductance value of the multilayer chip inductor decreases. Further, since the axial length of the coil L is increased, the number of turns that can be wound per unit length of the coil L is reduced, and a high inductance value cannot be obtained in the coil L.
JP 2001-358016 A

  Therefore, an object of the present invention is to provide a chip-type coil component that can reduce the resistance value of the coil without reducing the inductance value of the coil as much as possible.

  The present invention includes a laminate formed by laminating a plurality of insulator layers, a plurality of internal electrodes that are laminated on the insulator layer, and that form a coil by being connected to each other; An auxiliary internal electrode laminated on the insulator layer on which the internal electrode is laminated, and the auxiliary internal electrode is different from the insulator layer on which the auxiliary internal electrode is laminated The internal electrodes stacked on the body layer are connected in parallel.

  According to the present invention, since the auxiliary internal electrodes are connected in parallel to the internal electrodes stacked on different insulator layers, the resistance value of the coil can be reduced. Furthermore, since the auxiliary internal electrode is laminated on the insulator layer on which the internal electrode is laminated, it is not necessary to add a new insulator layer for the lamination of the auxiliary internal electrode. That is, even if the auxiliary internal electrode is provided, the axial length of the coil does not change. As a result, a decrease in the inductance value of the coil is suppressed.

  In the present invention, the auxiliary internal electrode may be insulated from the internal electrode laminated on the same insulator layer.

  In the present invention, the auxiliary internal electrode may be connected to the internal electrode laminated on the same insulator layer.

  In the present invention, the plurality of internal electrodes are connected via via-hole conductors, and one end of the auxiliary internal electrode is on the insulator layer different from the insulator layer on which the auxiliary internal electrode is laminated. It may be connected to the internal electrode laminated on the via hole conductor.

  In the present invention, the auxiliary internal electrode may be disposed in a region where the plurality of internal electrodes are stacked when viewed from the stacking direction.

  In the present invention, the auxiliary internal electrode may be connected to the internal electrode stacked on the insulator layer adjacent in the stacking direction.

  In the present invention, the insulator layer may be a magnetic layer.

  According to the present invention, since the auxiliary internal electrodes are connected in parallel to the internal electrodes laminated on different insulator layers, the resistance value of the coil is lowered without reducing the inductance value of the coil as much as possible. be able to.

1 is an external perspective view of a chip type coil component according to an embodiment of the present invention. The disassembled perspective view of the said chip type coil components. FIG. 3 is a perspective view of the chip-type coil component as viewed from above in the stacking direction. FIG. 4A is an equivalent circuit diagram of a conventional multilayer chip inductor. FIG. 4B is an equivalent circuit diagram of the chip-type coil component according to the embodiment of the present invention. The disassembled perspective view of the chip-type coil component which concerns on a 1st modification. The figure which showed the structure of the magnetic body layer of the chip type coil component which concerns on a 2nd modification, an internal electrode, and an auxiliary | assistant internal electrode. It is a disassembled perspective view of the 3rd prototype produced in the 2nd experiment. It is a disassembled perspective view of the 4th prototype produced in the 2nd experiment. The exploded perspective view of the conventional multilayer chip inductor.

(About the configuration of chip-type coil components)
Hereinafter, a configuration of a chip-type coil component according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an external perspective view of the chip-type coil component 10. FIG. 2 is an exploded perspective view of the chip-type coil component 10. In the following, the stacking direction is defined as the vertical direction. In the chip-type coil component 10, the upper end surface in the stacking direction is referred to as an upper surface, the lower end surface in the stacking direction is referred to as a lower surface, and the other surfaces are referred to as side surfaces.

  As shown in FIG. 1, the chip-type coil component 10 roughly includes a laminate 12 and external electrodes 14a and 14b. Furthermore, the laminate 12 has a built-in coil L.

  The laminated body 12 is a rectangular parallelepiped block, and a plurality of rectangular magnetic layers (insulator layers) 22, 20a, 20b, 20c, 20d, 20e, 20f, and 24 are laminated as shown in FIG. It is constituted by. In addition, when referring to the individual magnetic layer 20, the reference numerals are denoted by a to f, and when referring to the magnetic layer 20, the magnetic layer 20 is described. The magnetic layers 20, 22, and 24 are each made of a magnetic material. As an example of the magnetic material, for example, a Ni—Cu—Zn ferrite having a magnetic permeability of about 130 can be cited.

  The coil L is provided in the laminate 12 so that its axis coincides with the vertical direction. In the coil L, the internal electrodes 26a, 26b, 26c, 26d, 26e, and 26f are laminated on the magnetic layers 20a, 20b, 20c, 20d, 20e, and 20f, and the internal electrodes 26a, 26b, 26c, 26d, 26e, and 26f are configured by being electrically connected to each other in series. In addition, when referring to the individual internal electrodes 26, reference numerals are denoted by a to f, and when the internal electrodes 26 are generically referred to, the internal electrodes 26 are described. Further, the internal electrode 26 is laminated on the magnetic layer 20 when the internal electrode 26 is formed on the magnetic layer 20 by screen printing and the internal electrode 26 is transferred onto the magnetic layer 20. It is meant to include such cases.

  Each internal electrode 26 has a length of 3/4 turn, and is electrically connected in series via the internal electrode 26 and the via-hole conductor B stacked on the magnetic layer 20 adjacent in the vertical direction at the end thereof. It is connected. More specifically, the internal electrode 26a and the internal electrode 26b are electrically connected by a via hole conductor B1. The internal electrode 26b and the internal electrode 26c are electrically connected by a via hole conductor B2. The internal electrode 26c and the internal electrode 26d are electrically connected by a via hole conductor B3. The internal electrode 26d and the internal electrode 26e are electrically connected by a via hole conductor B4. The internal electrode 26e and the internal electrode 26f are electrically connected by a via hole conductor B5. Thereby, the coil L having a spiral shape is formed. Note that “3/4 turn” indicates that “U” -shaped electrodes are stacked along three of the four sides of the rectangular magnetic layer 20.

  Furthermore, the internal electrode 26a disposed in the uppermost layer includes a lead portion 28a, and the internal electrode 26f disposed in the lowermost layer includes a lead portion 28f. The lead portion 28a is electrically connected to the external electrode 14a shown in FIG. The lead portion 28f is electrically connected to the external electrode 14b shown in FIG. These internal electrodes 26 and via-hole conductors B are made of, for example, silver.

  The external electrodes 14a and 14b serve as terminals for electrically connecting the coil L and an external circuit, and are formed on the side surfaces of the stacked body 12 facing each other. The external electrodes 14a and 14b are produced, for example, by performing Ni plating and Sn plating on a silver electrode.

  Incidentally, in the chip-type coil component 10 according to the present embodiment, auxiliary internal electrodes 30a, 30b, 30c, 30d, 30e, and 30f are provided in order to reduce the resistance value of the coil L. In addition, when referring to the individual auxiliary internal electrodes 30, the reference numerals a to f are appended to the reference numerals, and when the auxiliary internal electrodes 30 are collectively referred to, the auxiliary internal electrodes 30 are described. Hereinafter, the auxiliary internal electrode 30 will be described.

  As shown in FIG. 2, each auxiliary internal electrode 30 is stacked in an empty region on the magnetic layer 20 on which the internal electrode 26 is stacked. However, the internal electrode 26 and the auxiliary internal electrode 30 stacked on the same magnetic layer 20 are insulated from each other. The auxiliary internal electrode 30 is electrically connected to the internal electrode 26 laminated on the magnetic layer 20 different from the magnetic layer 20 on which the auxiliary internal electrode 30 is laminated by the via-hole conductor b. Has been. More specifically, the auxiliary internal electrode 30 includes two via holes with respect to the magnetic layer 20 on which the auxiliary internal electrode 30 is stacked and the internal electrode 26 stacked on the magnetic layer 20 adjacent in the vertical direction. They are electrically connected in parallel via the conductor b. Hereinafter, the connection relationship between the internal electrode 26 and the auxiliary internal electrode 30 will be described in detail.

  The auxiliary internal electrode 30a is electrically connected in parallel to the internal electrode 26b by via-hole conductors b1 and b2. The auxiliary internal electrode 30b is electrically connected in parallel to the internal electrode 26c by via-hole conductors b3 and b4. The auxiliary internal electrode 30c is electrically connected in parallel to the internal electrode 26d by via-hole conductors b5 and b6. The auxiliary internal electrode 30d is electrically connected in parallel to the internal electrode 26e by via-hole conductors b7 and b8. The auxiliary internal electrode 30e is electrically connected in parallel to the internal electrode 26f by via-hole conductors b9 and b10. The auxiliary internal electrode 30f is electrically connected in parallel to the internal electrode 26e by via-hole conductors b11 and b12.

  As described above, since the auxiliary internal electrode 30 is connected in parallel to each internal electrode 26 in the chip type coil component 10, the resistance value of the coil L can be reduced. Furthermore, since the auxiliary internal electrode 30 is laminated in the empty area of the magnetic layer 20 where the internal electrode 26 is laminated, it is necessary to add a new magnetic layer 20 for the lamination of the auxiliary internal electrode 30. Absent. That is, even if the auxiliary internal electrode 30 is provided, the axial length of the coil L does not change. As a result, a decrease in the inductance value of the coil L is suppressed.

  Further, as shown in FIG. 3, the auxiliary internal electrode 30 is disposed so as not to protrude from the internal electrode 26 and to overlap with a region where the internal electrode 26 is laminated as viewed from above. FIG. 3 is a perspective view of the chip-type coil component 10 as viewed from above. As described above, the auxiliary internal electrode 30 and the internal electrode 26 overlap with each other, whereby the coil diameter of the coil L can be increased and the inductance value of the coil L can be increased.

  Moreover, since the chip-type coil component 10 is provided with the auxiliary internal electrode 30 as will be described below, the chip-type coil component 10 has better direct current superposition characteristics than a chip-type coil component not provided with the auxiliary internal electrode 30. It becomes like this. The auxiliary internal electrode 30 is made of, for example, silver. Since silver is a nonmagnetic material, in the chip-type coil component 10, a nonmagnetic material layer is provided between the magnetic material layers 20. As a result, the chip-type coil component 10 has better direct current superposition characteristics than the closed magnetic circuit-type chip-type coil component in which the auxiliary internal electrode 30 is not provided.

(Contrast with conventional multilayer chip inductor)
Hereinafter, in order to make the effect produced by the chip type coil component 10 clearer, the acquisition efficiency of the chip type coil component 10 and the acquisition efficiency of the conventional multilayer chip inductor shown in FIG. 9 are compared. The acquisition efficiency is a value obtained by dividing the coil inductance value by the resistance value.

  FIG. 4A is an equivalent circuit diagram of the conventional multilayer chip inductor shown in FIG. FIG. 4B is an equivalent circuit diagram of the chip-type coil component 10 shown in FIG. In FIG. 4A, only four magnetic layers 101 are described, and in FIG. 4B, only three magnetic layers 20 are described. In the multilayer chip inductor 14, 14 magnetic layers 101 are laminated, and in the chip type coil component 10, 6 magnetic layers 20 are laminated. However, since the acquisition efficiency does not change even if the number of layers is changed, the acquisition efficiency is compared below using the equivalent circuit diagrams of FIG. 4A and FIG. .

  The correspondence relationship between the equivalent circuit diagram shown in FIG. 4A and the multilayer chip inductor shown in FIG. 9 will be described below. LA is a combined inductance value of the internal electrode 102 laminated on each of the first magnetic layer 101 and the second magnetic layer 101. rAa + rAb is a resistance value of the internal electrode 102 laminated on the first magnetic layer 101. rAc + rAd is a resistance value of the internal electrode 102 laminated on the second magnetic layer 101.

  LB is a combined inductance value of the internal electrode 102 laminated on each of the third magnetic layer 101 and the fourth magnetic layer 101. rBa + rBb is a resistance value of the internal electrode 102 laminated on the third magnetic layer 101. rBc + rBd is a resistance value of the internal electrode 102 laminated on the fourth magnetic layer 101.

  Next, the correspondence between the equivalent circuit diagram shown in FIG. 4B and the chip-type coil component 10 shown in FIG. 2 will be described. L1 is an inductance value of the internal electrode 26 laminated on the first magnetic layer 20. r2c is a resistance value of the auxiliary internal electrode 30 laminated on the second magnetic layer 20. r1a + r1b is a resistance value of the internal electrode 26 laminated on the first magnetic layer 20. More specifically, r1b is the resistance value of the internal electrode 26 in the portion where the auxiliary internal electrodes 30 are connected in parallel, and r1a is the resistance value of the internal electrode 26 in the remaining portion.

  L2 is an inductance value of the internal electrode 26 laminated on the second magnetic layer 20. r3c is a resistance value of the auxiliary internal electrode 30 laminated on the third magnetic layer 20. r2a + r2b is a resistance value of the internal electrode 26 laminated on the second magnetic layer 20. r2b is the resistance value of the internal electrode 26 in the part where the auxiliary internal electrode 30 is connected in parallel, and r2a is the resistance value of the internal electrode 26 in the remaining part.

  L3 is an inductance value of the internal electrode 26 laminated on the third magnetic layer 20. r3a + r3b is a resistance value of the internal electrode 26 laminated on the third magnetic layer 20.

In the equivalent circuit diagram configured as described above, it is assumed that the following equations (1) and (2) hold.
rAa = rAc = rBa = rBc = r1a = r2a = r3a = R1 (1)
rAb = rAd = rBb = rBd = r1b = r2c = r2b = r3c = r3b = R2 (2)

  When Expression (1) and Expression (2) hold, the combined resistance value RdcI of the equivalent circuit diagram shown in FIG. 4A and the combined resistance value RdcII of the equivalent circuit diagram shown in FIG. (3) and (4).

RdcI = (R1 + R2) / 2 × 2 = R1 + R2 (3)
RdcII = (R1 + R2) + (R1 + R2 / 2) + (R1 + R2 / 2) = 3R1 + 2R2 (4)

  Here, the inductance value is proportional to the square of the number of turns of the coil and inversely proportional to the axial length of the coil. Therefore, when the inductance value of the equivalent circuit diagram shown in FIG. 4A is LI and the inductance value of the equivalent circuit diagram shown in FIG. 4B is LII, LI and LII are respectively expressed by equations (5) and ( As shown in 6).

LI = α · (2N) ² / 4λ = α · N ² / λ (5)
LII = α · (3N) ² / 3λ = α · 3N ² / λ (6)

  Α is a coefficient. Further, the axial length and the number of turns of the coil shown in the equivalent circuit diagram of FIG. 4A are 4λ and 2N, and the axial length and the number of turns of the coil shown in the equivalent circuit diagram of FIG. 4B are 3λ and 3N. . N is the length (number of turns) of the internal electrode for one layer (for example, 3/4 turn).

When obtaining the acquisition efficiency X1 of the equivalent circuit diagram of FIG. 4A and the acquisition efficiency X2 of the equivalent circuit diagram of FIG. 4B based on the equations (3) to (6), X1 and X2 are The results are as shown in equations (7) and (8), respectively.
X1 = α · N ² / [λ (R1 + R2)] (7)
X2 = α · 3N ² / [λ (3R1 + 2R2)] (8)

  According to the equations (7) and (8), it can be seen that X1 <X2. From the above, it can be said that the chip-type coil component 10 according to the present embodiment has higher acquisition efficiency than the conventional multilayer chip inductor shown in FIG.

(Modification)
FIG. 5 is an exploded perspective view of the chip-type coil component 10 ′ according to the first modification. In FIG. 5, the same reference numerals are assigned to the components corresponding to the components in FIG. Below, it demonstrates centering around the difference between chip type coil component 10 'which concerns on a 1st modification, and chip type coil component 10 shown in FIG.

  In the chip-type coil component 10 ′ according to the first modification, the internal electrode 26 and the auxiliary internal electrode 30 laminated on the same magnetic layer 20 are connected. Further, one end of the auxiliary internal electrode 30 connects the internal electrodes 26 to the internal electrode 26 laminated on the magnetic layer 20 different from the magnetic layer 20 on which the auxiliary internal electrode 30 is laminated. Are connected via via-hole conductors B. Specifically, the auxiliary internal electrode 30a is connected to the internal electrode 26b via the via-hole conductor B1 instead of the via-hole conductor b1. The auxiliary internal electrode 30b is connected to the internal electrode 26c via the via-hole conductor B2 instead of the via-hole conductor b4. The auxiliary internal electrode 30c is connected to the internal electrode 26d via the via-hole conductor B3 instead of the via-hole conductor b5. The auxiliary internal electrode 30d is connected to the internal electrode 26e via a via-hole conductor B4 instead of the via-hole conductor b7. The auxiliary internal electrode 30e is connected to the internal electrode 26f via a via-hole conductor B5 instead of the via-hole conductor b10. Note that the other end of each auxiliary internal electrode 30 is connected to the internal electrode 26 via a via-hole conductor b.

  The auxiliary internal electrode 30f laminated on the magnetic layer 20f is connected to the internal electrode 26f, and is connected to the internal electrode 26e via the via-hole conductor B5 instead of the via-hole conductor b11.

  According to the chip-type coil component 10 ′ according to the first modification as described above, the via-hole conductor for connecting the internal electrodes 26 to the via-hole conductor for connecting the auxiliary internal electrode 30 to the internal electrode 26 in parallel. Since B is also used, the total number of via-hole conductors b can be reduced. Therefore, productivity and cost reduction can be achieved in the chip-type coil component 10 ′.

  Further, according to the chip-type coil component 10 ′ according to the first modification, the length of the portion in which the internal electrode 26 and the auxiliary internal electrode 30 are connected in parallel as compared with the chip-type coil component 10 shown in FIG. Long. Therefore, the resistance values of r1b, r2b, r2c, r3c in the chip-type coil component 10 ′ according to the first modification are larger than the resistance values of r1b, r2b, r2c, r3c in the chip-type coil component 10 shown in FIG. growing. On the other hand, the resistance values of r1a and r2a in the chip-type coil component 10 ′ according to the first modification are smaller than the resistance values of r1a and r2a in the chip-type coil component 10 shown in FIG. Here, the amount of increase in the combined resistance value in the part connected in parallel is smaller than the amount of decrease in the resistance value in the remaining part. As a result, the resistance value RdcII of the chip-type coil component 10 ′ according to the first modification is smaller than the resistance value RdcII of the chip-type coil component 10 shown in FIG.

  In addition, since the chip-type coil component 10 ′ is provided with the auxiliary internal electrode 30 as in the case of the chip-type coil component 10, the direct current superposition better than the chip-type coil component without the auxiliary internal electrode 30. It has characteristics.

  FIG. 6 shows magnetic layers 20′a, 20′b, internal electrodes 26′a, 26′b, auxiliary internal electrodes 30′a1, 30′a2 of the chip-type coil component 10 ″ according to the second modification. FIG. As shown in FIG. 6, the internal electrodes 26'a and 26'b are stacked in a spiral shape. Two auxiliary internal electrodes 30′a1 and 30′a2 are stacked on the same magnetic layer 20′a. These auxiliary internal electrodes 30′a1 and 30′a2 are connected to the internal electrode 26′b stacked on the magnetic layer 20′b different from the stacked magnetic layer 20′a via via-hole conductors. The When three or more internal electrodes 26 ′ are provided, the auxiliary internal electrodes 30′a1 and 30′a2 may be connected to different internal electrodes 26 ′. Specifically, the auxiliary internal electrode 30′a1 is connected to the internal electrode 26 ′ stacked on the magnetic layer 20 ′ disposed above the magnetic layer 20 ′ on which the auxiliary internal electrode 30′a1 is stacked. The auxiliary internal electrode 30'a2 is connected to the internal electrode 26 'laminated on the magnetic layer 20' disposed below the magnetic layer 20 'on which the auxiliary internal electrode 30'a2 is laminated. Also good.

  Similarly to the chip-type coil component 10, the chip-type coil component 10 ″ has better direct current superimposition characteristics than the chip-type coil component not provided with the auxiliary internal electrode 30 ′.

  The auxiliary internal electrode 30 has two via-hole conductors b connected to the magnetic layer 20 on which the auxiliary internal electrode 30 is stacked and the internal electrode 26 stacked on the magnetic layer 20 adjacent in the vertical direction. However, the method for connecting the auxiliary internal electrodes 30 is not limited to this. The internal electrode 26 to which the auxiliary internal electrode 30 is connected is the internal electrode 26 other than the internal electrode 26 stacked on the magnetic layer 20 adjacent to the magnetic layer 20 in which the auxiliary internal electrode 30 is stacked in the vertical direction. It may be.

  Further, although the auxiliary internal electrode 30 is illustrated as overlapping the internal electrode 26 when viewed from above, the auxiliary internal electrode 30 may be disposed so as to protrude from the internal electrode 26.

  In the chip-type coil components 10 and 10 ′, a part of the magnetic layer 20 may be replaced with a nonmagnetic layer. In this case, the DC superimposition characteristics of the coil L are improved.

  Further, in the chip-type coil components 10, 10 ′, 10 ″, an insulating layer such as polyimide may be used instead of the magnetic layers 20, 22, 24.

(Experimental result)
In addition, the inventor of the present application conducted the following first and second experiments in order to make the effects exhibited by the chip-type coil components 10, 10 ′, 10 ″ clearer.

  In the first experiment, in order to show that the acquisition efficiency is improved in the chip-type coil component 10, a chip-type coil component (first prototype) in which the auxiliary internal electrode 30 is not stacked and the auxiliary internal electrode 30 A laminated chip-type coil component 10 (second prototype) was prototyped, and each inductance value, resistance value, and acquisition efficiency were measured.

  First, the prototype chip-type coil component will be described. The configuration of the first prototype and the second prototype is as follows. The difference between the first prototype and the second prototype is only the presence or absence of the auxiliary internal electrode 30.

Size: 2.00mm x 1.25mm x 0.85mm
Magnetic layer material: Ni—Cu—Zn ferrite magnetic layer permeability: 130
Material of external electrode: Ni-plated and Sn-plated internal electrode on silver and material of auxiliary internal electrode: Length of silver internal electrode: Number of turns of 3/4 turn coil L: 6.5 turns

  The inductance value, resistance value, and acquisition efficiency in the first prototype and the second prototype as described above were as shown in Table 1.

  According to Table 1, it can be understood that the inductance value of the second prototype is slightly decreased as compared with the inductance value of the first prototype by laminating the auxiliary internal electrodes 30. However, it can be understood that the resistance value of the second prototype is significantly lower than the resistance value of the first prototype. As a result, it can be understood that the acquisition efficiency of the second prototype is greatly improved over the acquisition efficiency of the first prototype. From the above, it can be understood that the acquisition efficiency of the chip-type coil component 10 is improved by providing the auxiliary internal electrode 30. From the result of the first experiment, it can be said that the chip-type coil components 10 ′ and 10 ″ have improved acquisition efficiency as with the chip-type coil component 10.

  Next, a second experiment will be described with reference to the drawings. FIG. 7 is an exploded perspective view of a third prototype produced in the second experiment. FIG. 8 is an exploded perspective view of a fourth prototype produced in the second experiment. Note that the chip-type coil component 10′a according to the third prototype shown in FIG. 8 differs from the chip-type coil component 10 ′ in the number of turns of the coil L, and the magnetic layer 20f is a non-magnetic layer 40f. It has the same configuration except that it is replaced with.

  In the second experiment, in order to show that the DC superimposition characteristics have been improved in the chip-type coil component 10 ′, the chip-type coil component 50 (third prototype) shown in FIG. And a chip-type coil component 10′a (fourth prototype) shown in FIG. 8 on which the auxiliary internal electrode 30 is laminated, and the respective resistance values are measured and the current is not flowing. Each inductance value (first inductance value) and acquisition efficiency (first acquisition efficiency), each inductance value (second inductance value) and acquisition efficiency (second acquisition efficiency) when a current of 300 mA flows. ) Was measured.

  First, the prototype chip-type coil component will be described. The configuration of the third prototype and the fourth prototype is as follows. The difference between the third prototype and the fourth prototype is only the presence or absence of the auxiliary internal electrode 30.

Size: 2.00mm x 1.25mm x 0.85mm
Magnetic layer material: Ni—Cu—Zn ferrite magnetic layer permeability: 130
Non-magnetic layer material: Cu-Zn ferrite Non-magnetic layer position: One layer in the center Material of external electrode: Ni-plated and Sn-plated internal electrode on auxiliary silver and auxiliary internal electrode material: length of silver internal electrode S: Number of turns of 5/6 turn coil L: 9.5 turns

  The resistance values, inductance values, and acquisition efficiencies of the third and fourth prototypes as described above were as shown in Table 2.

  According to Table 2, in the third prototype, by passing a current of 300 mA, the second inductance value is reduced by 30% compared to the first inductance value. On the other hand, in the fourth prototype, by passing a current of 300 mA, the second inductance value is reduced by only 22% from the first inductance value. Therefore, it can be seen that the decrease rate of the inductance value of the fourth prototype is smaller than the decrease rate of the inductance value of the third prototype. From the above, it can be understood that the provision of the auxiliary internal electrode 30 improves the direct current superposition characteristics of the chip-type coil component 10′a. From the results of the second experiment, it can be said that the DC superimposition characteristics of the chip-type coil components 10 and 10 '' are also improved as in the case of the chip-type coil component 10'a.

  Furthermore, the fourth prototype has superior direct current superposition characteristics compared to the third prototype. Therefore, the fourth prototype can obtain an inductance value higher than that of the third prototype even when a current is applied. As a result, the fourth prototype can have a higher second acquisition efficiency than the third prototype. From the above, it can be seen that the provision of the auxiliary internal electrode 30 allows the chip-type coil component 10′a to obtain higher acquisition efficiency than the chip-type coil component 50 even when a current is applied. It can be said that the chip-type coil components 10 and 10 ″ have improved acquisition efficiency in a state where a current is applied, similarly to the chip-type coil component 10′a.

(About manufacturing method)
Below, the manufacturing method of the chip-type coil component 10 is demonstrated, referring FIG.1 and FIG.2.

First, ceramic green sheets used as the magnetic layers 20, 22, and 24 are produced. For example, 48.0 mol% of ferric oxide (Fe ₂ O ₃ ), 25.0 mol% of zinc oxide (ZnO), 18.0 mol% of nickel oxide (NiO), and 9.0 mol% of copper oxide (CuO) Each material weighed in the above ratio is put into a ball mill as a raw material, and wet blending is performed. The obtained mixture is dried and pulverized, and the obtained powder is calcined at 750 ° C. for 1 hour. The obtained calcined powder is wet pulverized by a ball mill, dried and then crushed to obtain a ferrite ceramic powder.

  A binder (vinyl acetate, water-soluble acrylic, etc.), a plasticizer, a wetting material, and a dispersing agent are added to the ferrite ceramic powder, followed by mixing with a ball mill, and then defoamed under reduced pressure. The obtained ceramic slurry is formed into a sheet by a doctor blade method and dried to produce a ceramic green sheet having a desired film thickness.

  Next, via hole conductors B and b shown in FIG. 2 are formed on the ceramic green sheet used as the magnetic layer 20. A through hole is formed in the ceramic green sheet using a laser beam or the like, and the through hole is filled with a conductive paste such as Ag, Pd, Cu, Au, or an alloy thereof by a method such as printing and coating. , B.

  Next, the internal electrode 26 and the auxiliary internal electrode 30 are formed on the main surface of the ceramic green sheet on which the via-hole conductors B and b are formed by applying a conductive paste by a method such as screen printing or photolithography. To do.

  Next, ceramic green sheets are laminated to form an unfired mother laminate. At this time, the ceramic green sheets are preliminarily pressure-bonded by overlapping a predetermined number of sheets. Then, when all the temporary pressure bonding is completed, the main pressure bonding of the mother laminated body is performed using hydrostatic pressure or the like.

  Next, the unfired mother laminate is cut into individual laminates using a dicer or the like. Thereby, a rectangular parallelepiped laminated body is obtained.

  Next, the binder is subjected to a binder removal process and firing. Thereby, the baked laminated body 12 is obtained.

  Next, a silver electrode having a shape as shown in FIG. 1 is formed on the surface of the laminate 12 by applying and baking an electrode paste whose main component is silver by a known method such as a dipping method. .

  Finally, the external electrodes 14a and 14b are completed by performing Ni plating and Sn plating or Ni plating and solder plating on the surface of the baked silver electrode. Through the above steps, the chip-type coil component 10 as shown in FIG. 1 is completed.

When a part of the magnetic layer 20 is replaced with a non-magnetic layer, it is necessary to produce a ceramic green sheet used for the non-magnetic layer. Specifically, such a ceramic green sheet is produced as follows. Ferrous oxide (Fe ₂ O ₃ ) 48.0 mol%, zinc oxide (ZnO) 43.0 mol%, and copper oxide (CuO) 9.0 mol% were weighed into the ball mill using the respective materials as raw materials. Add and do wet blending. The obtained mixture is dried and pulverized, and the obtained powder is calcined at 750 ° C. for 1 hour. The obtained calcined powder is wet pulverized with a ball mill, dried and crushed to obtain a nonmagnetic ceramic powder.

  A binder (vinyl acetate, water-soluble acrylic, etc.), a plasticizer, a wetting material, and a dispersing agent are added to the nonmagnetic ceramic powder and mixed by a ball mill, and then defoamed by decompression. The obtained ceramic slurry is formed into a sheet shape by a doctor blade method and dried to produce a ceramic green sheet used for the nonmagnetic layer.

  In addition, although the sheet | seat lamination method was demonstrated as a manufacturing method of the chip type coil component 10, the manufacturing method of the chip type coil component 10 is not restricted to this. For example, the chip-type coil component 10 may be manufactured by a sequential printing lamination method or a transfer lamination method.

  Further, in the chip-type coil component 10, when an insulating layer such as polyimide is used instead of the magnetic layers 20, 22, and 24, the insulating layer is formed by a thick film printing method, a sputtering method, a CVD method, or the like. It is formed by combining the film forming method of the method and the photolithography technique.

  As described above, the present invention is useful for chip-type coil components, and is particularly excellent in that the resistance value of the coil can be reduced without reducing the inductance value of the coil as much as possible.

Claims (7)

A laminate formed by laminating a plurality of insulator layers;
A plurality of internal electrodes stacked on the insulator layer and connected to each other to form a coil; and
An auxiliary internal electrode laminated on the insulator layer on which the internal electrode is laminated;
With
The auxiliary internal electrode is connected in parallel to the internal electrode laminated on the insulator layer different from the insulator layer on which the auxiliary internal electrode is laminated;
Chip-type coil parts characterized by The auxiliary internal electrode is insulated from the internal electrode laminated on the same insulator layer;
The chip-type coil component according to claim 1, wherein: The auxiliary internal electrode is connected to the internal electrode laminated on the same insulator layer;
The chip-type coil component according to claim 1, wherein: The plurality of internal electrodes are connected via via-hole conductors,
One end of the auxiliary internal electrode is connected via the via-hole conductor to the internal electrode laminated on the insulator layer different from the insulator layer on which the auxiliary internal electrode is laminated. thing,
The chip-type coil component according to claim 3, wherein: The auxiliary internal electrode is disposed in a region where the plurality of internal electrodes are stacked when viewed from the stacking direction;
The chip-type coil component according to any one of claims 1 to 4, wherein: The auxiliary internal electrode is connected to the internal electrode stacked on the insulator layer adjacent in the stacking direction;
The chip-type coil component according to any one of claims 1 to 5, wherein: The insulator layer is a magnetic layer;
The chip-type coil component according to any one of claims 1 to 6, wherein:

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